UTI's and Cold Weather - Is there a link?

Over the past few quarters of data the QPS consultants have noticed that the rate of Urinary Tract Infections has been higher (2-4%) in New Zealand than for Australia. More recently we have noticed that for many of the cold climate facilities in New Zealand, Tasmania and Southern Victoria a common trend of higher winter UTI rates. The trends being noticed are typified by the following four facility trend graphs from facilities in the above mentioned areas.

Whilst not every cold climate aged care facility experiences this trend, it is quite common for cold climate facilities to experience higher rates of UTI in quarter 4 (April - June) - the period in which the onset of winter occurs. It is also noticed that the overall rate of UTI's for the whole QPS data base (high and low care) increases e.g. the rate for Quarter 2 (October - December - early summer) was 11.28% whilst the rate for Q4 (April-June - early winter) was 12.95%. This equates to a 1.67% increase in UTI's from summer 2008 to winter 2009.

QPS consultants have had several discussions with facility managers during the data cleaning period and several hypotheses were put forward to explain the trends. These include:

  • Staff do not focus as much on hydration regimes uduring the cooler months.
  • Central heating systems that are normally switched on from April onwards can have a drying out impact.
  • Residents tend to wear more clothes in winter and will put off going to the toilet due to the increased difficulty in getting their clothes off or exposing themselves to the colder conditions.

QPS forwarded this information to the QPS infection control advisor, Catherine Lamond from Infection Control Professionals. Catherine conducted a literature search on the subject and found the following:

Foxman B, Somsel P, et al; Journal of Clinical Epidemiology 2001, Jul;54 (7): 710-8 - Department of Epidemiology, University of Michigan School of Public Health.

In this case-control study the researchers explored the role of a number of health and behavioural factors on UTI risk among women aged 40-65 in Michigan and Israel. One of the factors identified significantly more frequently among UTI cases than controls was a recent episode of cold hands, feet, back or buttocks lasting longer than 30 minutes.

Baerhiem A, Laerum E ; Scandanavian Journal of Primary Health Care, 1993, Dec:11 (4) 289-90 - Department of Public Health and Primary Health Care, University of Bergen, Norway.

In this open, non randomised experimental study the researchers similarly found that "cooling of the feet seems to provoke symptomatic lower UTI in cystitis-prone women". This study was conducted on women in a wider age range.

In this study "29 health women aged 19-68 (mean 42.5 ) years who had three or more symptomatic episodes of UTI during the previous 12 months were included. They registered symptoms and carried out a strip urinalysis at each urination during a 72 hour control period. Their lower legs and feet were then immersed in increasingly cold water for 30 minutes. Another 72 hour period of registration followed. Six subjects developed acute distal urinary symptoms.......compared with none in the control period."

Prior to this article QPS asked 7 managers of the facilities with higher winter UTI trends to comment on their data. One pleasing aspect was the fact that almost all managers were aware of the results and had discussed the results with staff. The comment from Karen Lusty at Kapiti Trust in New Zealand was typical of the responses received:

"Funnily enough we had recently had a registered staff meeting and had been discussing our benchmarking result in this area. We had come up with exactly the same theories too and encouraged the caregivers to be vigilant and offering fluids more frequently than maybe they were in the winter months. I will be interested to hear what your results are and what the article says in respect to this trend."

Catherine Lamond from Infection Control Professionals adds:

The findings of these two studies are interesting and thought-provoking. They would suggest that we should widen the scope of our attempts to prevent UTIs in susceptible residents. As well as the more familiar strategies of ensuring adequate fluids and encouraging regular toileting, we should actively work to keep residents warm in the winter months. In view of the body parts specified, use of gloves, socks and adequate undergarments should be particularly targeted.